Unit 1 Flashcards
What is electricity
movement of e-
What is ampere
strength of the current (charge over time)
What is electric field
force exerted by an electric charge
What is electrical potential energy
the energy needed to affect other electric charges
What is impedance
opposition to the magnitude and phase of a current
What is resistance
opposition to the magnitude of a current (similar to friction)
What is capacitance
ratio of the change in an electric charge
What is DC
electric current that is unchanging; resistance and impedance are the same
What is AC
electric current that periodically reverses direction; resistance and impedance are not the same
What is magnetic field
vector field created by electric charges in relative motion
What is electrodynamics
the interaction s between electric charges and currents
What is electromagnet
magnetic field created by an electrical curren
What is magnetic domain
region of a magnetic field that is in a uniform direction
What is magnetic susceptibility
extent to which a material is affected by a magnet
What is Tesla
unit of measure for magnetic force (1T=10,000G)
What is Gauss
unit of measure for magnetic force (earth’s magnetic force = 0.5G)
What is the phase
waveform of going through a complete cycle
What is electromagnetic induction
production of a current due to the motion of a magnetic field
What is electromagnetic radiation
EM waves interactions w/ matter
How do like and unlike electric charges interact
likes repel; opposites attract
how does distance affect the strength of electrostatic charges
inverse square law
Ohm’s Law
I=V/R
I - current; V - voltage; R - resistance
Describe an insulator
resists the effects of a current
Describe a conductor
easily carries a current
Describe a semiconductor
conductivity between an insulator and a conductor
Describe a superconductor
conductor that never loses a current
Ferromagnetic
highly susceptible to magnetic force
paramagnetic
partially susceptible to magnetic force
Diamagnetic
not affected by magnetic force
Temporary magnet
magnetization is applied or removed when exposed to a magnetic force
Permanent magnet
magnetization isn’t affected by a magnetic force
How do like and unlike magnetic poles interact
opposites attract; likes repel
how does distance affect magnetic field strength
inverse square law
Faraday’s Law (of electromagnetic induction)
V = -dB/dt
V - Electromotive force; dB - change in the magnetic field; dt - change in time
types of impedance
Resistors - release of energy through heat
Capacitor (plates) - energy is stored in an electric field
Inductor (coils) - energy is stored in a magnetic field
physical causes of electromagnetic radiation
radio waves, light, heat
What are the orientations of the magnetic domains in a magnet?
they oscillate, 90 degrees out of phase, perpendicular to each other
How is the magnetic field affected if a current is looped?
amplifies the magnetic field
What is the orientation of an induced magnetic field to the current
counter clockwise (right hand rule)
What do the waveforms look like when they are in phase?
overlapping sine waves
What do the waveforms look like when they are 90 degrees out of phase?
sine and cosine waves
What do the waveforms look like when they are 180 degrees out of phase?
sine and -sine waves
